package com.micro.school.common.core.utils.file;

import com.micro.school.common.core.constant.Constants;
import com.micro.school.common.core.exception.file.FileNameLengthLimitExceededException;
import com.micro.school.common.core.exception.file.FileSizeLimitExceededException;
import com.micro.school.common.core.exception.file.InvalidExtensionException;
import com.micro.school.common.core.utils.DateUtils;
import com.micro.school.common.core.utils.SpringUtils;
import com.micro.school.common.core.utils.StringUtils;
import com.micro.school.common.core.utils.uuid.Seq;
import org.apache.commons.io.FilenameUtils;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.Objects;
import java.util.concurrent.CompletableFuture;

/**
 * 文件上传工具类
 *
 * @author ruoyi
 */
public class FileUploadUtils
{
    /**
     * 默认大小 50M
     */
    public static final long DEFAULT_MAX_SIZE = 50 * 1024 * 1024L;

    /**
     * 默认的文件名最大长度 100
     */
    public static final int DEFAULT_FILE_NAME_LENGTH = 100;



    /**
     * 根据文件路径上传至oss
     *
     * @param file 上传的文件
     * @return 文件名称
     * @throws IOException
     */
    public static final String upload2OSS(MultipartFile file) throws IOException
    {
        try
        {
            return upload2OSS(file, MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION);
        }
        catch (Exception e)
        {
            throw new IOException(e.getMessage(), e);
        }
    }

    /**
     * 文件上传至oss
     *
     * @param file 上传的文件
     * @param allowedExtension 上传文件类型
     * @return 返回上传成功的文件名
     * @throws IOException 比如读写文件出错时
     */
    public static final String upload2OSS(MultipartFile file, String[] allowedExtension)
            throws Exception
    {
        int fileNamelength = Objects.requireNonNull(file.getOriginalFilename()).length();
        if (fileNamelength > FileUploadUtils.DEFAULT_FILE_NAME_LENGTH)
        {
            throw new FileNameLengthLimitExceededException(FileUploadUtils.DEFAULT_FILE_NAME_LENGTH);
        }

        assertAllowed(file, allowedExtension);

        // 生成OSS对象名
        String objectName = OssUtil.generateOSSObjectName(file);

        try
        {
            // 获取线程池
            ThreadPoolTaskExecutor threadPoolTaskExecutor = SpringUtils.getBean("threadPoolTaskExecutor");

            // 异步上传文件到OSS
            CompletableFuture<String> future = OssUtil.uploadToOSSAsync(
                    file,
                    objectName,
                    threadPoolTaskExecutor.getThreadPoolExecutor()
            );

            // 获取上传结果（URL）
            String url = future.get();

            // 返回URL
            return url;
        }
        catch (Exception e)
        {
            throw new IOException("上传文件到OSS失败：" + e.getMessage(), e);
        }
    }


    /**
     * 编码文件名
     */
    public static final String extractFilename(MultipartFile file) {

        return StringUtils.format("{}/{}.{}", DateUtils.datePath(), Seq.getId(Seq.uploadSeqType), getExtension(file));
    }

    public static final File getAbsoluteFile(String uploadDir, String fileName) throws IOException
    {
        File desc = new File(uploadDir + File.separator + fileName);

        if (!desc.exists())
        {
            if (!desc.getParentFile().exists())
            {
                desc.getParentFile().mkdirs();
            }
        }
        return desc;
    }

    /**
     * 文件大小校验
     *
     * @param file 上传的文件
     * @return
     * @throws FileSizeLimitExceededException 如果超出最大大小
     * @throws InvalidExtensionException
     */
    public static final void assertAllowed(MultipartFile file, String[] allowedExtension)
            throws Exception
    {
        long size = file.getSize();
        if (size > DEFAULT_MAX_SIZE)
        {
            throw new FileSizeLimitExceededException(DEFAULT_MAX_SIZE / 1024 / 1024);
        }

        String fileName = file.getOriginalFilename();
        String extension = getExtension(file);
        if (allowedExtension != null && !isAllowedExtension(extension, allowedExtension))
        {
            if (allowedExtension == MimeTypeUtils.IMAGE_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidImageExtensionException(allowedExtension, extension,
                        fileName);
            }
            else if (allowedExtension == MimeTypeUtils.FLASH_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidFlashExtensionException(allowedExtension, extension,
                        fileName);
            }
            else if (allowedExtension == MimeTypeUtils.MEDIA_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidMediaExtensionException(allowedExtension, extension,
                        fileName);
            }
            else if (allowedExtension == MimeTypeUtils.VIDEO_EXTENSION)
            {
                throw new InvalidExtensionException.InvalidVideoExtensionException(allowedExtension, extension,
                        fileName);
            }
            else
            {
                throw new InvalidExtensionException(allowedExtension, extension, fileName);
            }
        }
    }

    /**
     * 判断MIME类型是否是允许的MIME类型
     *
     * @param extension
     * @param allowedExtension
     * @return
     */
    public static final boolean isAllowedExtension(String extension, String[] allowedExtension)
    {
        for (String str : allowedExtension)
        {
            if (str.equalsIgnoreCase(extension))
            {
                return true;
            }
        }
        return false;
    }

    /**
     * 获取文件名的后缀
     *
     * @param file 表单文件
     * @return 后缀名
     */
    public static final String getExtension(MultipartFile file)
    {
        String extension = FilenameUtils.getExtension(file.getOriginalFilename());
        if (StringUtils.isEmpty(extension))
        {
            extension = MimeTypeUtils.getExtension(Objects.requireNonNull(file.getContentType()));
        }
        return extension;
    }
}
